October 2019 - phenixbb - phenix-online.org

positional restraints in real_space_refine?
by Daniel Larsson 08 Oct '19

08 Oct '19

Hi all, I'm working on a cryo-EM reconstruction where I have some flexible low-resolution elements (RNA double helices). They have different orientations relative to my reference model, but I would like to model them in the approximately correct position. I've tried real_space_refine with morphing and simulated annealing, but neither accomplish what I want. Now I'm thinking of cutting out these helices and manually position them approximately where I want them. But I fear that this will case headache at the "joint". Is it possible to use the manual positions as a reference for positional restraints, but use the original model as the reference for the torsion angles. Is this possible with real_space_refine? Or is there a better way of refining this structure? Regards, Daniel När du har kontakt med oss på Uppsala universitet med e-post så innebär det att vi behandlar dina personuppgifter. För att läsa mer om hur vi gör det kan du läsa här: http://www.uu.se/om-uu/dataskydd-personuppgifter/ E-mailing Uppsala University means that we will process your personal data. For more information on how this is performed, please read here: http://www.uu.se/en/about-uu/data-protection-policy

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Phenix 1.17-3644 installation problems
by Hernando J Sosa 08 Oct '19

08 Oct '19

Dear Phenix developers, Trying to install Phenix in a Linux computer (OpenSuse Leap 15.1)I got the error messages listed below. Any help to fix this problem(s) would be appreciated. Thks. H. Precompiling .py files... Generating SOLVE/RESOLVE license file... Rebuilding HTML documentation... Error rebuilding documentation! Creating rotamer/Ramachandran database files... Traceback (most recent call last): File "./bin/install.py", line 244, in <module> installer(sys.argv[1:]).install() File "/home/hsxx/Downloads/phenix-installer-1.17-3644-intel-linux-2.6-x86_64-centos6/lib/libtbx/auto_build/install_distribution.py", line 201, in install self.install_finalize() File "/home/hsxx/Downloads/phenix-installer-1.17-3644-intel-linux-2.6-x86_64-centos6/lib/libtbx/auto_build/install_distribution.py", line 542, in install_finalize self.product_specific_finalize_install(log) File "./bin/install.py", line 130, in product_specific_finalize_install call([os.path.join(self.build_dir, 'bin', 'mmtbx.rebuild_rotarama_cache')], log=log) File "/home/hsxx/Downloads/phenix-installer-1.17-3644-intel-linux-2.6-x86_64-centos6/lib/libtbx/auto_build/installer_utils.py", line 53, in call raise RuntimeError("Call to '%s' failed with exit code %d" % (args, rc)) RuntimeError: Call to '/home/hsxx/Programs/Phenix/phenix-1.17-3644/build/bin/mmtbx.rebuild_rotarama_cache' failed with exit code -4

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reference torsion restraints for nucleic acids in real_space_refine
by Daniel Larsson 08 Oct '19

08 Oct '19

Hi all, In phenix.real_space_refine, I'm using a reference model for torsion restraints for a RNA/protein complex. I noticed in the log file under the section "Adding Reference Model Restraints (torsion)" that only the amino acid residues and some modified nucleotides are listed in the "Reference Model Matching Summary" but not the standard nucleotides. Does this mean that they are not restrained? I checked the _initial.geo file and there are no torsion restraints for the standard nucleotides in the "Reference torsion angle restraints" section. Are they not supported by default? My workflow was this: run ready_set on the initial model and then supply real_space_refine with a reference model and the ready_set cif file with the ligands. Regards, Daniel När du har kontakt med oss på Uppsala universitet med e-post så innebär det att vi behandlar dina personuppgifter. För att läsa mer om hur vi gör det kan du läsa här: http://www.uu.se/om-uu/dataskydd-personuppgifter/ E-mailing Uppsala University means that we will process your personal data. For more information on how this is performed, please read here: http://www.uu.se/en/about-uu/data-protection-policy

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Base-pair restraints and high resolution cryoEM maps
by Stephen Cusack 08 Oct '19

08 Oct '19

Dear All, (1) Is it possible to add RNA base-pair restraints into Phenix Real-space-refinement of a lowish resolution cryoEM structure? If so how? (2) We are also lucky enough to have some impressively high resolution cryoEM maps (2.4 A average) which show among other things hundreds of water molecules. I was wondering whether Phenix Real-space-refinement was really adapted to high resolution, e.g. it uses grouped B-factor refinement and has no water handling options (putting them in manually is a pain and you always miss some). How have other people dealt with these issues ? thanks for any help Stephen Cusack -- ********************************************************************** Dr. Stephen Cusack, FRS Head of EMBL Grenoble Group leader in the structural biology of protein-RNA complexes and viral proteins ********************************************************************** Email: cusack(a)embl.fr, stephen.cusack(a)embl.org Website: http://www.embl.fr Tel: (33) 4 76 20 7238 Secretary (33) 4 76 20 7123 Fax: (33) 4 76 20 7199 Postal address: EMBL Grenoble Outstation, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble Cedex 9, France Delivery address: EMBL Grenoble Outstation, Polygone Scientifique, 71 Avenue des Martyrs, 38000 Grenoble, France **********************************************************************

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PhD and postdoc position - Structural Biology Methods development at Wuerzburg University
by Andrea Thorn 07 Oct '19

07 Oct '19

Dear colleagues, for two projects in structural biology methods development, we are looking for a PHD CANDIDATE (m/f/d) and a POSTDOCTORAL RESEARCHER (m/f/d) The Thorn Laboratory the Rudolf Virchow Center at the University of Wuerzburg develops new methods for macromolecular X-ray crystallography and Cryo-EM. In these exciting projects you will improve how well we understand, measure and model macromolecular crystal structures using practical experiments and big data analyses. We are looking for candidates with skills in data analysis and programming. Any previous experiences in crystallography, molecular biology, machine learning, image or statistical analysis are also a bonus. You should be a good communicator. For the PhD project, we offer a 36-month full- or part-time position, embedded in the Würzburg Graduate School for Life Sciences (GSLS); for the postdoctoral position, we offer a 30-month full- or part-time position with a competitive salary as well as career and family support. Women are particularly encouraged to apply. For more details, see: https://www.uni-wuerzburg.de/fileadmin/43020000/2019/Stellenanzeige_PhD_Tho… https://www.uni-wuerzburg.de/fileadmin/43020000/2019/Stellenanzeige_Postdoc… If you have any questions, please email me: andrea.thorn(a)uni-wuerzburg.de. Best wishes, Andrea Thorn. _____ Dr. Andrea Thorn group leader Rudolf Virchow Center for Experimental Biomedicine University of Wuerzburg Josef-Schneider-Str. 2 97080 Wuerzburg Germany andrea.thorn(a)uni-wuerzburg.de https://www.uni-wuerzburg.de/en/rvz/research/associated-research-groups/tho…

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Position Available: Crystallography Facility Manager (Research Assistant Professor) - CUNY Advanced Science Research Center, New York City
by Keedy, Daniel 04 Oct '19

04 Oct '19

To the phenixbb community, The Structural Biology Initiative ( https://asrc.gc.cuny.edu/structbio ) of the CUNY Advanced Science Research Center has an available position for an X-ray Crystallography Facility Manager (Research Assistant Professor) starting immediately. The CUNY Advanced Science Research Center is a new cutting-edge research institution located in New York City, bringing together five Initiatives whose research areas span many length scales: Structural Biology, Nanoscience, Photonics, Neuroscience, and Environmental Science. The Structural Biology Initiative (SBI) features seven tenure-track and research faculty members, pursuing research problems across biological and chemical topics using techniques as diverse as X-ray diffraction, cryo-EM, NMR, solution biophysics, and advanced microscopy. The SBI also hosts state-of-the-art core facilities in three different areas: nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry (MS), and X-ray crystallography. The Structural Biology Initiative seeks a Facility Manager/Research Assistant Professor for the X-ray Macromolecular Crystallography Facility, which is already equipped with a Rigaku Alchemist DT liquid handler, two ARI Gryphon crystallization robots, and two Rigaku Minstrel DT crystal imagers at room temperature and 4°C. The selected candidate will be responsible not only for directing day-to-day operations of the facility in concert with users from the ASRC and externally, but also for developing an independent research program that leverages emerging technologies in X-ray crystallography. The ASRC is located in upper Manhattan, immediately adjacent to the New York Structural Biology Center (NYSBC), a consortium of CUNY and eight other New York academic institutions with world-class cryo-EM, NMR, and X-ray facilities on-site and at Brookhaven National Laboratory. BNL, located just 70 miles from the ASRC, includes a newly constructed synchrotron, National Synchrotron Light Source II, which opened in 2015. NSLS-II is now the brightest synchrotron light source in the United State, offering X-rays that are 10,000x brighter than the original NSLS. The ASRC Structural Biology Initiative has access to several cutting-edge microfocus beamlines equipped for automated crystal handling and data collection at NSLS-II, including the NYX beamline via CUNY’s membership in NYSBC and the AMX and FMX beamlines via proposals. Please find more detailed information about the position and officially apply via the following URL: https://cuny.jobs/new-york-ny/macromolecular-crystallization-facility-manag… Review of applications will begin on October 16. Best regards, Daniel Keedy — Daniel A. Keedy, Ph.D. Assistant Professor Structural Biology Initiative, CUNY Advanced Science Research Center Department of Chemistry and Biochemistry, City College of New York Biochemistry and Chemistry Ph.D. Programs, CUNY Graduate Center www.keedylab.org<http://www.keedylab.org> | dkeedy(a)gc.cuny.edu<mailto:[email protected]> (NOT @asrc) | 212-413-3246

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Re: [phenixbb] Figure of merit from refinement
by Alexandre OURJOUMTSEV 03 Oct '19

03 Oct '19

Dear Andre, (I repeat here the same message that I've just sent through the ccp4bb; sorry for answering late) I would strongly advice you to look at the article by Lunin and Skovoroda (Acta Cryst, A, 1995) that addresses exactly your question: https://scripts.iucr.org/cgi-bin/paper?vs0124 The authors remind a very important point that after model refinement ML phase errors are strongly underestimated if using all reflections, as that was done in the original works (see references in the article). While the same ML estimates work perfectly for unrefined models, that's not the case for refined ones, as was observed yet in the beginning of 80ths. These authors show then that using the test-set of reflections (the same as for R-free) is crucial to get the correct phase error estimates and respective FOMs for all cases, as this is implemented now in modern refinement programs, e.g. phenix.refine. See also the article by Pannu & Read (Acta Cryst, A, 1996) https://onlinelibrary.wiley.com/doi/pdf/10.1107/S0108767396004370 A more recent important article on this topic is that by Praznikar and Turk (Acta Cryst, D, 2009) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4257616/ who discuss what can be done if a statistically significant test set of reflections is not available. I hope this helps you. I am ready to answer you further eventual questions (probably, in a private correspondence). With best wishes, Sacha Urzhumtsev ________________________________ -------- Forwarded Message -------- Subject: [phenixbb] Figure of merit from refinement Date: Tue, 1 Oct 2019 08:15:14 -0300 From: Andre LB Ambrosio <andre(a)ifsc.usp.br><mailto:[email protected]> To: phenixbb(a)phenix-online.org<mailto:[email protected]> Dear all, How is the FOM calculated for a given reflection specifically in the context of model refinement? How useful is it in assessing the phase quality, when not for initial experimental phases? Many thank in advance, -- Andre LB Ambrosio

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Figure of merit from refinement
by Andre LB Ambrosio 01 Oct '19

01 Oct '19

Dear all, How is the FOM calculated for a given reflection specifically in the context of model refinement? How useful is it in assessing the phase quality, when not for initial experimental phases? Many thank in advance, -- Andre LB Ambrosio

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